1999

5.2

2003

5.1

1994

7.3

1996

6.9

1995

6.2

1997

6.2

1996

7.2

1990

6.9

2005

6.2

1988

6.8

2006

5.4

2001

6.3

1996

6.4

2019

7.7

1977

6.8

1992

5.3

1998

7.1

1987

7.0

1987

6.9

2006

7.1